1import os
2from distutils import log
3import itertools
4
5from six.moves import map
6
7
8flatten = itertools.chain.from_iterable
9
10
11class Installer:
12
13    nspkg_ext = '-nspkg.pth'
14
15    def install_namespaces(self):
16        nsp = self._get_all_ns_packages()
17        if not nsp:
18            return
19        filename, ext = os.path.splitext(self._get_target())
20        filename += self.nspkg_ext
21        self.outputs.append(filename)
22        log.info("Installing %s", filename)
23        lines = map(self._gen_nspkg_line, nsp)
24
25        if self.dry_run:
26            # always generate the lines, even in dry run
27            list(lines)
28            return
29
30        with open(filename, 'wt') as f:
31            f.writelines(lines)
32
33    def uninstall_namespaces(self):
34        filename, ext = os.path.splitext(self._get_target())
35        filename += self.nspkg_ext
36        if not os.path.exists(filename):
37            return
38        log.info("Removing %s", filename)
39        os.remove(filename)
40
41    def _get_target(self):
42        return self.target
43
44    _nspkg_tmpl = (
45        "import sys, types, os",
46        "has_mfs = sys.version_info > (3, 5)",
47        "p = os.path.join(%(root)s, *%(pth)r)",
48        "importlib = has_mfs and __import__('importlib.util')",
49        "has_mfs and __import__('importlib.machinery')",
50        "m = has_mfs and "
51            "sys.modules.setdefault(%(pkg)r, "
52                "importlib.util.module_from_spec("
53                    "importlib.machinery.PathFinder.find_spec(%(pkg)r, "
54                        "[os.path.dirname(p)])))",
55        "m = m or not has_mfs and "
56            "sys.modules.setdefault(%(pkg)r, types.ModuleType(%(pkg)r))",
57        "mp = (m or []) and m.__dict__.setdefault('__path__',[])",
58        "(p not in mp) and mp.append(p)",
59    )
60    "lines for the namespace installer"
61
62    _nspkg_tmpl_multi = (
63        'm and setattr(sys.modules[%(parent)r], %(child)r, m)',
64    )
65    "additional line(s) when a parent package is indicated"
66
67    def _get_root(self):
68        return "sys._getframe(1).f_locals['sitedir']"
69
70    def _gen_nspkg_line(self, pkg):
71        # ensure pkg is not a unicode string under Python 2.7
72        pkg = str(pkg)
73        pth = tuple(pkg.split('.'))
74        root = self._get_root()
75        tmpl_lines = self._nspkg_tmpl
76        parent, sep, child = pkg.rpartition('.')
77        if parent:
78            tmpl_lines += self._nspkg_tmpl_multi
79        return ';'.join(tmpl_lines) % locals() + '\n'
80
81    def _get_all_ns_packages(self):
82        """Return sorted list of all package namespaces"""
83        pkgs = self.distribution.namespace_packages or []
84        return sorted(flatten(map(self._pkg_names, pkgs)))
85
86    @staticmethod
87    def _pkg_names(pkg):
88        """
89        Given a namespace package, yield the components of that
90        package.
91
92        >>> names = Installer._pkg_names('a.b.c')
93        >>> set(names) == set(['a', 'a.b', 'a.b.c'])
94        True
95        """
96        parts = pkg.split('.')
97        while parts:
98            yield '.'.join(parts)
99            parts.pop()
100
101
102class DevelopInstaller(Installer):
103    def _get_root(self):
104        return repr(str(self.egg_path))
105
106    def _get_target(self):
107        return self.egg_link
108